International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B6. Istanbul 2004 
  
The planning of the control points is thus done for the set of 20 
photographs for which aerial triangulation is carried out. Figure 
5 shows a sketch of a control point and the students in the field 
measuring it. 
  
Ficha de Campo dos Ponios de Controlo 
Topografia #7 
  
N° da Fiada w 
Ponio 
M do Ponto ıs N° das fotografías 18271322 
  
  
Coordenadas do 
d o-26478 972 m 
N: 100771.92? m 
C: H.905 m 
  
Data: 4-m-eoo2 
Local: gus 
  
Tipo de Ponlo 
Fotogvumétrico 
Controlo 
  
  
  
  
  
  
Legends 
- Porto eeddo 
  
  
  
Figure 5. Measuring the control points 
The measurements of the control points were done with a 
Trimble GPS, using the relative method. An example of the 
final output, produced by one of the students group, is 
illustrated in Figure 6, showing the planimetric information 
extracted with the Photogrammetric Image Station SSK Pro of 
Zeiss/Intergraph, for an area corresponding to a single 
stereoscopic model. This planimetric information still needs 
verification, which is a task well suited for the subsequent 
semester with : theme of Cartographic Production. The 
gathering of the corresponding altimetric information is, by way 
of standard, addressed in the autonomous discipline of 
Orthophotocartography (see Table 1). 
5. FINAL CONSIDERATIONS 
A committee was installed to accompany and evaluate the 
implementation of PBL at the ESTGA. The first evaluation 
results revealed a generally positive response by the students. In 
particular the clear-cut resemblances of the learning 
environment with the future working environment contribute to 
a stronger motivation of the students. Some negative notes must 
also be mentioned, most notably with respect to the expected 
workload, difficulties in planning and keeping work schedules, 
and difficulties in assuming the new role division between 
students and teachers. Also from the perspective of the teachers, 
this new role division constitutes a major challenge with 
noticeable implications ranging from logistic and organisational 
aspects to the human side of relating to students as well as 
colleagues. 
66 
  
Figure 6. Partial restitution of a model for a topographic map at 
scale 1:2.000 
To conclude, we want to point out a number of specific topics 
that present important challenges for the future of PBL at 
ESTGA: 
- the integration of all the facets of the pedagogic 
model; 
- the evaluation of the model and its results, as different 
from the evaluation of individual staff members; 
- the development of a “culture of institution” that 
avoids a return to the traditional pedagogic model; 
- the implementation of measures to stimulate and duly 
reward staff members for a demanding involvement 
in pedagogic activities. 
With respect to the Photogrammetric Restitution theme in 
particular, the reaction of the students is enthusiastic. They 
learn all the photogrammetric process in an integrated manner 
starting with planning, passing by measuring of control points 
and finishing with extraction of the geo-information, according 
to specifications. At the end of the semester, the students are 
equipped with the skills necessary to work in a production 
environment, except for, in the majority of cases, precise 
measuring in stereo which requires hard training. 
REFERENCES 
D. and Feletti, G. (eds), 1991. The Challenge of 
Problem-Based Learning. Kogan Page, London. 
Boud,